1. Field of the Invention
The present invention relates to a device and method for determining the position of an object, and more particularly to a device and method for determining a touch position used in a touch control device.
2. Description of Related Art
The coordinate of an object is detected in a certain touch control device to use as the input information of a character, pattern or symbol corresponding to it, or the input information of an interactive electric game machine.
U.S. Pat. No. 4,762,990 discloses a data processing input interface determining the position of an object, comprising an object located in a work area surrounded by reflecting members located at peripheral borders, a source of a scanning light beam for scanning the beam across the work area from an initial start position, means for determining the position of the object within said work area by measurement of the rotational arc of the scan of a single light beam from the initial start position to rotational angles represented by serially occurring signals produced by the beam striking the object after reflection from the reflecting member located at a peripheral border and directly striking the object.
Taiwan Publishing Patent No. 201104533 discloses a multi-touch input apparatus, including a touch panel for inputting at least one touch point, at least one light source surrounding the touch panel to provides detecting light, and a plurality of imaging systems positioned on the adjacent corners of the touch panel to detect the shielding light angle of the touch point, where the plurality of imaging systems have a first visual angle and a second visual angle. The multi-touch input apparatus uses the shielding light angle of the touch point detected by different visual angles of the imaging systems to determine the touch points corresponding to the shielding light angle, and calculates by trigonometric formula to get the coordinates of the touch points.
But, an object is blocked by another object when the two objects and a scanning light beam are on the same line, the technologies of the Taiwan patent and the U.S. Patent mentioned above are unable to be used to detect the coordinate of the blocked object.